Display devices may utilize various technologies for displaying images, such as cathode ray tube (CRT) technologies, projection-based technologies, liquid crystal display (LCD)-based technologies, etc. Some display devices may also be configured to detect touches of physical objects on a surface of the display, using technologies such as capacitive detection, resistive detection, optical detection, etc. In some cases, optical detection technologies may be further configured to detect “near-touches” of physical objects located near a surface of the display.
A computing system which combines the functionality of a display device and optical detection such as an infrared vision subsystem may have one or more features compromised as a result of integrating the two technologies. As an example, such a display system may combine a projection-based display system with a standard infrared vision subsystem, however, use of the projection-based display may significantly increase the cost of such a system. Use of an LCD display may be more cost-effective, however the standard configurations employed to provide infrared vision can interfere with the LCD backlight. As a result, the overall form factor may need to be altered to avoid such interference, and/or it may be necessary to employ various optics to minimize the effects on the LCD display. Such optics can have constraints (e.g., focal length, optical path length, depth of field, depth of focus, etc.) which dictate a larger form factor for the display. Further, such optics may increase distortion, aberration, etc. of the obtained image, and may not be suitable for high-quality imaging applications.